An exception might be thrown by emplace_back

vector::emplace_back might throw and prevent
libvlc_audio_output_device_list_release from being called

This reverts commit 9d2e6edb.
This makes more sense, since most of libvlc_*_release functions will
either assert or assume that the given pointer is non null.
Since shared_ptr will call the deleter for any pointer (including
nullptr), we're better of refusing to wrap a pointer and avoid undefined
behavior

This reverts commit 8e8c1672.
This feels too much like a bad idea.

VS2015 (partially) supports constexpr

The lambda was unnecessary overhead since we can easily provide a
function pointer instead

Since it contains callbacks, not events.

Thomas Nigro authored May 12, 2015 and Hugo Beauzée-Luyssen committed May 12, 2015

Signed-off-by: Hugo Beauzée-Luyssen <hugo@beauzee.fr>

Return a bool instead of an int & allow default interface to be selected

Own a reference instead, and document the behavior

This is likely to break under MSVC

The later is not portable